Tip - curved sides help with movement of the media,

I did a make shift one a few years ago. used two round washing up bowls placed top to top and cut a hole out in the top one. fixed that to a board which was mounted on springs to a lower board. Fixed a spare ac motor to the bottom board with a lump of metal with an offset hole in to mount to the motor spindle. All done!

Sorry for lack of detail but recon you get the idea, now off to workshop.